WV 42 is a north/south route that extends from Petersburg to the border with Maryland. It begins at WV 28/WV 55. The first section, known as Lunice Creek Highway, runs north to Scherr, where it ends at Laurel Dale Road (WV 93). WV 42 is then multiplexed with WV 93 along Union Highway up a mountain to pass under Corridor H (US 48). Just after the overpasses, WV 93 splits off onto Power Station Highway. Union Highway continues north to Mount Storm, where it ends at George Washington Highway (US 50). WV 42 is multiplexed with US 50 to the east for a few miles and then splits off and runs north to Elk Garden, where it is known as Cottage Street. Just north of Elk Garden, it crosses into Maryland and becomes Kitzmiller Road (MD 38).